Elevated levels of isoprostanes are suspected of contributing to increased risk of heart attack in patients taking Coxibs[citation needed]. Isoprostanes and their metabolites have also been shown to be elevated in the urine of cigarette smokers, and have been suggested as biomarkers of oxidative stress in smokers.[6]

Polyunsaturated fatty acids other than arachidonic acid are also vulnerable to reactive oxygen species and produce isoprostanes. For example, in addition to the four classes of F2-isoprostanes that can arise from arachidonic acid, peroxidation of eicosapentaenoic acid (EPA) is predicted to lead to the generation of six classes of F3 isoprostanes, α-linolenic and γ-linolenic acids to two classes of E1- and F1-isoprostanes, and docosahexaenoic acid to eight classes of D4-isoprostanes and eight classes of E4-isoprostanes. Each of the classes comprise up to eight racemic isomers, leading to an astounding number of isoprostane molecules.[7]